Synthetic biology aims to make biology easier to engineer. Synthetic biology is the convergence of advances in chemistry, biology, computer science, and engineering that enables us to go from idea to product faster, cheaper, and with greater precision than ever before. It can be thought of as a biology-based “toolkit” that uses abstraction, standardization, and automated construction to change how we build biological systems and expand the range of possible products. A community of experts across many disciplines is coming together to create these new foundations for many industries, including medicine, energy and the environment. It’s early days yet – biology is complex and messy and doesn’t follow the same rules as computer code. But increasingly, scientists are learning how to use synthetic biology to change how organisms operate – including insects that carry dangerous human diseases, such as Zika.
INTRODUCTION TO THE PROBLEM
During the summer months, mosquitoes are as common as backyard barbecues and swimming pools. Unfortunately, they bring with them not only the discomfort of the occasional bite, but also the possibility of transmitting human and animal diseases. Knowledge about mosquito biology and habitat can help us better control these pests. Individual homeowners can play a significant role in this process, but sometimes a community effort is needed. Regardless, you can do many things, including using insect repellents, to reduce your chance of being bitten by a mosquito. mosquitoes transmit a range of pathogens that cause substantial human morbidity, mortality, and suffering. Dengue, the most important mosquito-borne viral disease with 50–400 million infections per year worldwide.
Using synthetic biology-based genetic engineering techniques, the British company Oxitec (owned by U.S.-based Intrexon Corp) has successfully added a genetic switch to Aedes aegypti mosquitoes, the species that carries dengue and Zika. As long as the insects are fed the antibiotic tetracycline, the switch remains off and the bugs are fine. But remove the drug, and the switch is activated – preventing genes from working, and ultimately killing the mosquito. It’s a trait that enables the controlled decimation of wild mosquito populations. The key is that this genetic kill switch is inherited by the Oxitec mosquitoes’ offspring. When modified male mosquitoes (which don’t bite) are released, they mate with wild females and pass on the trait before dying, ensuring that a sizable portion of the next generation of tetracycline-starved wild mosquitoes die before reaching maturity. Repeat this a few times, and you eradicate the local Aedes aegyptimosquito population.
In 2005, the synthetic biology pioneer Drew Endy outlined an audacious and thought-provoking vision for “engineering biology ” in the journal Nature. One idea is particularly relevant to emerging infectious diseases like Zika: using synthetic biology to rapidly develop vaccines. Vaccines typically involve exposing a patient to inactive viruses or to materials that mimic the specific features of these viruses that trigger an immune response. The aim is to stimulate the immune system into building immunity, without it being exposed to a live, and potentially deadly, virus. Using traditional techniques, developing vaccines can be a long and arduous process. However, researchers are now looking at how they can digitize viral DNA and RNA sequences, and use these to rapidly design and produce new vaccines that activate the immune system in the same way as the virus, without causing infection. And synthetic biology is also opening up the possibility of “smart vaccines” that can be programmed to produce a range of different molecules that trigger an immune response, as and when needed. A unique advantage of this approach is that, once the genetic code for a vaccine has been developed, it can be distributed digitally. It becomes – in principle – possible to produce vaccines on-site, on demand. No slow, risky physical distribution – just the vaccine that you want, when you want it, at the press of a button.
efore we get there, though, a third use of synthetic biology may be employed that makes vaccines redundant: gene drives. In November 2015, microbiologist Anthony James at the University of California Irvine and his colleagues demonstrated how heritable traits – in this case a genetic intolerance of the parasite responsible for malaria – can be spread through an entire population. What they showed in effect is that, using synthetic biology, whole species can be reengineered with designer traits. The concept is called a “gene drive,” and it’s been around for a while. But only with the advent of precise gene editing techniques such as CRISPRhave they become feasible. CRISPR is a genetic “search and replace” technique that allows scientists to target and swap out specific DNA sequences. On its own, this isn’t enough to transform a whole species – every time a CRISPR mosquito (for instance) mated with an unmodified mosquito, the designer-code would be diluted. But here’s the clever bit. Imagine that CRISPR is used to insert a genetic sequence in a mosquito that not only prevents it from hosting the malaria parasite but also includes a copy of the same CRISPR “search and replace” code. Now, whenever the original DNA sequence reappears – for instance, in the genes of offspring after mating with an unmodified mosquito – that embedded code would search out the original genes that support the malaria parasite and replace them with the new modified genes. In this way, the modification would be transmitted down through every generation of mosquitoes, until all that remained was a human-designed species that is unable to host the malaria parasite.
Three ways synthetic biology could annihilate Zika and other mosquito-borne diseases
INTRODUCTION TO SYNTHETIC BIOLOGY
[[image:blob:http://bli-research-synbio-2017-session-1.wikispaces.com/c295a66f-e81d-40c0-92fc-8aa59a94beb1]]
Synthetic biology aims to make biology easier to engineer. Synthetic biology is the convergence of advances in chemistry, biology, computer science, and engineering that enables us to go from idea to product faster, cheaper, and with greater precision than ever before. It can be thought of as a biology-based “toolkit” that uses abstraction, standardization, and automated construction to change how we build biological systems and expand the range of possible products. A community of experts across many disciplines is coming together to create these new foundations for many industries, including medicine, energy and the environment. It’s early days yet – biology is complex and messy and doesn’t follow the same rules as computer code. But increasingly, scientists are learning how to use synthetic biology to change how organisms operate – including insects that carry dangerous human diseases, such as Zika.
INTRODUCTION TO THE PROBLEM
During the summer months, mosquitoes are as common as backyard barbecues and swimming pools. Unfortunately, they bring with them not only the discomfort of the occasional bite, but also the possibility of transmitting human and animal diseases. Knowledge about mosquito biology and habitat can help us better control these pests. Individual homeowners can play a significant role in this process, but sometimes a community effort is needed. Regardless, you can do many things, including using insect repellents, to reduce your chance of being bitten by a mosquito.
mosquitoes transmit a range of pathogens that cause substantial human morbidity, mortality, and suffering. Dengue, the most important mosquito-borne viral disease with 50–400 million infections per year worldwide.
[[image:blob:http://bli-research-synbio-2017-session-1.wikispaces.com/c4dc4db6-8e29-42a6-baab-ac8361d892ff]][[image:blob:http://bli-research-synbio-2017-session-1.wikispaces.com/07362c9b-d182-4443-9b68-879247c27e8b width="393" height="257"]]
Using synthetic biology-based genetic engineering techniques, the British company Oxitec (owned by U.S.-based Intrexon Corp) has successfully added a genetic switch to Aedes aegypti mosquitoes, the species that carries dengue and Zika. As long as the insects are fed the antibiotic tetracycline, the switch remains off and the bugs are fine. But remove the drug, and the switch is activated – preventing genes from working, and ultimately killing the mosquito.
It’s a trait that enables the controlled decimation of wild mosquito populations.
The key is that this genetic kill switch is inherited by the Oxitec mosquitoes’ offspring. When modified male mosquitoes (which don’t bite) are released, they mate with wild females and pass on the trait before dying, ensuring that a sizable portion of the next generation of tetracycline-starved wild mosquitoes die before reaching maturity.
Repeat this a few times, and you eradicate the local Aedes aegyptimosquito population.
[[image:blob:http://bli-research-synbio-2017-session-1.wikispaces.com/43a3ddd7-de06-4871-b871-7b7b89e716eb]][[image:blob:http://bli-research-synbio-2017-session-1.wikispaces.com/dc4a9ba5-8ad9-4bdf-9bad-83ecb0a28d8c width="365" height="281"]]
2. Fast vaccine development and instant delivery
In 2005, the synthetic biology pioneer Drew Endy outlined an audacious and thought-provoking vision for “engineering biology ” in the journal Nature. One idea is particularly relevant to emerging infectious diseases like Zika: using synthetic biology to rapidly develop vaccines.
Vaccines typically involve exposing a patient to inactive viruses or to materials that mimic the specific features of these viruses that trigger an immune response. The aim is to stimulate the immune system into building immunity, without it being exposed to a live, and potentially deadly, virus.
Using traditional techniques, developing vaccines can be a long and arduous process. However, researchers are now looking at how they can digitize viral DNA and RNA sequences, and use these to rapidly design and produce new vaccines that activate the immune system in the same way as the virus, without causing infection. And synthetic biology is also opening up the possibility of “smart vaccines” that can be programmed to produce a range of different molecules that trigger an immune response, as and when needed.
A unique advantage of this approach is that, once the genetic code for a vaccine has been developed, it can be distributed digitally. It becomes – in principle – possible to produce vaccines on-site, on demand. No slow, risky physical distribution – just the vaccine that you want, when you want it, at the press of a button.
[[image:blob:http://bli-research-synbio-2017-session-1.wikispaces.com/80cda4b0-1291-43cf-879b-00e8223a76c8 width="380" height="283"]][[image:blob:http://bli-research-synbio-2017-session-1.wikispaces.com/9e3fa794-4759-46ae-95f5-b3d49f214d5a width="477" height="285"]]
3- Gene drives could redesign a whole species
efore we get there, though, a third use of synthetic biology may be employed that makes vaccines redundant: gene drives.
In November 2015, microbiologist Anthony James at the University of California Irvine and his colleagues demonstrated how heritable traits – in this case a genetic intolerance of the parasite responsible for malaria – can be spread through an entire population. What they showed in effect is that, using synthetic biology, whole species can be reengineered with designer traits.
The concept is called a “gene drive,” and it’s been around for a while. But only with the advent of precise gene editing techniques such as CRISPRhave they become feasible.
CRISPR is a genetic “search and replace” technique that allows scientists to target and swap out specific DNA sequences. On its own, this isn’t enough to transform a whole species – every time a CRISPR mosquito (for instance) mated with an unmodified mosquito, the designer-code would be diluted. But here’s the clever bit.
Imagine that CRISPR is used to insert a genetic sequence in a mosquito that not only prevents it from hosting the malaria parasite but also includes a copy of the same CRISPR “search and replace” code. Now, whenever the original DNA sequence reappears – for instance, in the genes of offspring after mating with an unmodified mosquito – that embedded code would search out the original genes that support the malaria parasite and replace them with the new modified genes.
In this way, the modification would be transmitted down through every generation of mosquitoes, until all that remained was a human-designed species that is unable to host the malaria parasite.
[[image:blob:http://bli-research-synbio-2017-session-1.wikispaces.com/19e13e3b-9114-4c59-9e33-5da947268d1a width="328" height="263"]][[image:blob:http://bli-research-synbio-2017-session-1.wikispaces.com/d099e629-a73a-4aa5-9077-a764f549ddcd width="485" height="247"]]
Presentation
https://drive.google.com/open?id=0B9nltiYNzGMNZElsVEdQRjV3RFE
REFRENCES